Are you asking if you can take C++ code for QNX and compile this into windows exe file with Visual Studio and run this exe on Windows? If you are asking that, the answer is no, or at least no, not without some work to port the code into Windows.

Or are you asking if you can use the Momentic IDE to compile QNX executables under Windows and then run the executables on a QNX machine? If you are asking that, the answer is yes, Momentics allows cross compiling in Windows to create QNX exe's.